Finally done. My #SegaMegaDrive has a new enclosing now. 50/60Hz and language switches moved from the top to the back. Added proper stereo audio out jacks and s-video out which provides a nice crisp image.
Finally got a defective #segamegadrive from EBay (bottom) in order to replace the scratched shell of my device. LED does not light up, power switch feels broken. Let's see if the poor thing is beyond repair now.
Played "World of Illusion" with the offspring today. I forgot how much fun the two player cooperative mode is. Are there any other non-/low-violent games for the #segamegadrive/#segagenesis with a similar two player mode?